Vascular heparan sulfates may limit the ability of leukocytes to penetrate the endothelial barrier--implications for use of glucosamine in inflammatory disorders.

Oral glucosamine has anti-inflammatory activity in rodents, and anecdotal evidence suggests that it may be clinically useful in inflammatory bowel disorders. A possible explanation is that supplemental glucosamine increases production of heparan sulfate (HS) proteoglycans by the vascular endothelium, thereby improving the endothelium's barrier function. Extravasation of leukocytes and metastatic cancer cells requires degradation of HS. Heparin can inhibit neutrophil activation, adhesion, and chemotaxis, and--like glucosamine--has been reported effective for managing inflammatory bowel syndromes. Cytokine-mediated loss of endothelial HS may be a key factor in the coordinated inflammatory response. These considerations suggest that glucosamine may have clinical utility in a range of inflammatory disorders, and should be assessed with regard to its impact on cancer metastasis and peripheral ischemic disease. In inflammatory bowel disease, fish oil, ginkgolides, and enteric-coated 5-aminosalicylic acid may safely complement the efficacy of glucosamine.